HMOX1 and colon carcinoma: Our previous study demonstrated that CoPP inhibited LPS‐ or lipoteichoic acid (LTA)‐induced inducible nitric oxide (NO) synthase (iNOS) and NO production by microglia.22 Although several biological activities of HO‐1 induced by CoPP have been reported, the effect of HO‐1 on the viability of human colon carcinoma cells is still undefined.